Frontotemporal lobar degeneration (FTLD), formerly called Pick's disease, is a progressive neurodegenerative disease affecting the frontal and anterior temporal lobes. In 1998, consensus criteria for FTLD defined three clinical syndromes, all hypothesized to be linked by underlying similarities in neuropathology. These include frontotemporal dementia (FTD) (also called the frontal variant of FTD), semantic dementia (also called the temporal variant of FTD), and nonfluent aphasia. Despite some overlap in regional atrophy with Alzheimer's disease (AD), the distinctive anatomic patterns of neurodegeneration seen with the three major FTLD subtypes allow their separation from most patients with AD and from each other based upon clinical features and neuroimaging patterns. The neuropathology associated with FTLD is distinctive from AD and does not involve aggregation of Aβ-42.
This chapter will provide an overview of the diagnostic, pathologic, genetic, imaging, and treatment advances in the recent literature concerning FTLD. Case studies will be used to illustrate the main findings and to provide clinicians with a sense of the varied presentations of the disease. Continuum Lifelong Learning Neurol 2007;13(2):87-108.